Grinder – Buying Guide, Opinions and Analysis
Knives, drill bits, screwdrivers… they all need to go through the grinder from time to time to get their edge back. Grinders are a type of tool, usually electric, with a built-in grinding wheel that is used to sharpen and polish (grind) any surface. Among the best equipment on the market you will find the Bosch Professional GBG with double grit grinding wheel, perfect for drills of all kinds or the Einhell TH-US 240, a mixed equipment, with grinding wheel and band for all types of tools.
The 8 Best Grinders – Opinions 2022
Grinders are characterized by their simplicity and usefulness. They are abrasive machining tools that use grinding wheels and belts driven by electric motors. In the market you will find a wide variety of grinders, with features and options for all needs. Next, we detail the 8 best.
1. Bosch Professional GBG 60-20 Bench grinder
This double bench grinder is made up of two 24 and 60 caliber grinding discs with protection shields and a 600 W motor, capable of rotating at 3600 revolutions per minute (RPM). It is a very solid piece of equipment, with a very powerful induction motor, perfect for the toughest applications.
The casing is made of cast material, making it a very robust product, ideal for screwing into a bench. It has encapsulated ball bearings that keep the motor free of dust, on the other hand it offers good stability, thanks to its four anchor points and rubber supports that secure the bracket and prevent vibrations. Overall, it’s the best grinder for a shop as it’s built to last a long time.
Induction motor: The 600 W induction motor is one of its main features, since it allows to work with large pieces.
Supports : The support with four anchor points and the rubber supports, improve stability and eliminate vibrations.
Dual Disc : Dual 24 and 60 gauge grit discs allow you to tackle any job, even on tough materials.
Cleaning : It does not have a hatch to clean or vacuum the dust that accumulates in the grinder, which can reduce its useful life or cause breakdowns.
2. Scheppach 5903306901 SM150LB Bench grinder
This bench grinder is suitable for any sanding, sharpening or polishing job. The machine has a 60-gauge coarse-grit grinding disc and a brush-type grinding disc with aluminum bristles for polishing and burnishing metal surfaces and preparing them for welding.
It is one of the best grinders of 2022 for workshops, since it has interchangeable multifunction discs. Its cast iron frame and LED work lights give this machine all the tools to work in a workshop.
Its 0.5 horsepower and 400 W power motor offers a rotational speed of 2850 RPM. In addition, it has spark protection technology that extends the life of the motor and prevents electrical failures.
Double disc : By having a grain disc and another brush type, it offers greater versatility, without having to invest in accessories.
Motor : The motor has a very solid construction that will allow you to use the grinder at a professional and intensive level.
LED light: The LED lights on the grinding discs are a perfect complement, especially if you are going to use the machine in a workshop.
Power of the lights : The LED lights do not work with the electrical power of the machine, but they do it with batteries. This supposes an extra investment.
3. Einhell TH-US 240 Combination Grinder
Einhell is considered by many users to be the best brand of grinders and electric machines on the market. This combination grinder features a sanding belt and a coarse grit (80 gauge) abrasive disc. All the components of this equipment have a high quality finish, which guarantees the best results.
The wheel has an adjustable spark protection glass to improve safety during work. The body is made of forged metals, so it is robust and resistant, it also has four rubber feet to improve support and eliminate vibrations during operations.
It has a light 240 W motor, with a ball bearing shaft without play, which allows more precise work and unusual power in such cheap models.
Protector : The protective glass of the grinding disc offers greater safety when working, since it can be adjusted and adjusted in height.
Support : The four support feet improve the stability of the equipment and prevent vibrations.
Band : Being a combined grinder, it has a sanding band that can be used to sharpen and sand metal surfaces.
Weight : The security screws can be threaded and the fastening of the band and the grinding wheel can be somewhat loose. This is due to the use of lightweight materials.
4. Ryobi 5133002857 Sander Grinder
If you are wondering what is the best sander grinder for a workshop, Ryobi is one of the best options. It is a perfect machine for professional cabinetmakers, carpenters and mechanics of all kinds. Also great for sharpening and balancing all kinds of cutting and garden tools.
The induction motor of 370 W and 2850 RPM offers a very stable power, especially considering that it is one of the cheapest machines you will find on the market. This combination grinder features a dust extraction nozzle and is made of cast steel to improve stability and eliminate vibration.
It has a 150 mm diameter grinding wheel, which can be changed for a brush disc and a sanding band, in addition the disc has an adjustable glass protector to protect the user from sparks and an upper LED light to illuminate the area of job.
Here are the pros and cons of this cheap grinder to help you decide if it’s the one you need.
Design : The housing made of cast steel is very strong and stable, designed to withstand work without vibration.
Versatility : It is a very versatile piece of equipment, since it has a grinding wheel and a sanding band. The grinding wheel can be changed and a brush disc or any disc with different grain sizes can be installed.
Power : Due to its 370 W motor, it is not the best option to face heavy and serial work, since it can overheat.
5. Moracle Combined Belt Sanding Disc
This belt grinder includes a 4×36 inch belt sander and a 150mm fine grit disc. The belt is adjustable and tilts between 0 and 90 degrees, allowing the machine to be used for horizontal and vertical sanding.
The grinder motor, with 750 W and a speed of 1420 RPM, offers a very high performance, so if you are wondering which grinder to buy for your woodworking workshop, this could be the best possibility.
The motor frame is made of cast metal and machined aluminum and the base is robust with four legs to improve stability and prevent vibrations. In addition, the table has an inclination for work of up to 45 degrees, which allows you to carry out a series of precision tasks, something unusual in cheap grinders.
Inclination : The inclination of the work table and the belt make it a very versatile piece of equipment, perfect for precision machining.
Weight : The machine, with the belt and disc installed, weighs 15 Kg, so you can easily move it.
Power : The 750 W motor allows you to work on most materials, even the hardest.
Accessories : Although it is a cheap grinder, it does not have accessories such as LED work lights or protection glasses.
6. KKmoon Vertical Sand Belt Machine
For many users, this is the best grinder of the moment in terms of portability. It is a belt and multifunctional grinder, very compact and very low in weight. It has a very low noise level, thanks to its light 90 W motor.
The vertical adjustment wheel design offers many grinding and sharpening options, both for drill bits and for all types of tools. It is made of high-quality metal, with anti-corrosion protection and wear resistance, so it has a long service life.
It has a solid structure, with automatic tension adjustment spring, built-in double bearing, non-slip studs and anti-dust filtering system. The base is stable, with four anchor points for screws, and can be placed on a table, as the studs absorb vibrations.
Size : Being a very compact size machine and being made of lightweight materials, it can be easily transported.
Adjustment : The table has free adjustment options, it can be slided up and down as well as angled.
Spare parts: The sanding belts of this machine have a non-standard size, which makes it difficult to access spare parts once the grain of the original belt is worn.
7. Cevik CP10-15 Grinding Sandpaper
This Cevik sander grinder has a power of 450 W and 2800 RPM, ideal for roughing, sharpening and sanding different types of materials. You will be able to sharpen blades, drill bits, saws and all kinds of cutting tools, as well as grind hard materials, both metal and wood, and rectify cuts. In addition, thanks to the belt sander you can work the wood finishes.
The wheels have a diameter of 150 mm and are made of corundum, with coarse grain, it is also a resistant and stable machine, with rubber feet that absorb vibrations and allow you to work more efficiently.
The power button is protected against dust and has a glass protector for the grinding wheel. For all this, it could be the best value for money grinder.
Dual function : The dual function, with wheels and sanding belt, allows the user to perform a wide variety of jobs from sanding to grinding.
Design : The body of the grinder has a solid and attractive design, with four rubber feet that offer stability and absorb vibrations.
Size : Being a small and light grinder, it does not have great power. This is noticeable, above all, in the sanding belt that stops if very hard pieces are used.
grinder for sharpening knives
8. Peugeot ENERGY Grind 100 Water sharpener
This knife sharpener is a fast and efficient solution that allows you to extend the life of all your knives and cutting tools. The wheel is 100 mm in diameter and is easy to change, it also has a water system, which moistens the wheel, to prevent friction and protect the edge.
Its switch has protection against sparks and the motor has a power of 53 W and 230 V, with a rotation of 250 RPM, it is also very stable and robust, with a construction that absorbs vibrations and improves the final result of sharpening.
Grinding wheel: This is a grinder dedicated exclusively to sharpening knives and cutting tools, so the grinding wheel is designed for this task.
Price : It is the cheapest grinder on the list, since for a low price it allows you to sharpen and recover all your tools.
Size : It is a very compact grinder, so it does not work well with large tools, even having problems with the axis.
Grinders are very useful in carpentry and mechanical workshops, as well as for any DIY enthusiast. Not only do they allow you to recover the sharpness of your tools and bits, but they are ideal for grinding parts, polishing and grinding and machining of all kinds. Next, we explain what are the main factors that you should look at when buying one.
To start with this guide to buying the best grinder, we will talk about the different types of grinders on the market, each with its own characteristics. The most common are bench grinders, which usually weigh between 6 and 7 kg, with a pair of grinding discs mounted on a shaft. These are used to sharpen drill bits, chisels, lathe blades, screwdrivers, and other tools.
There are also pedestal grinders, which do not need a bench, since they incorporate their own pedestal. They are bigger, with larger discs and more powerful motors. The pedestal allows them to absorb vibrations completely, so they tend to be more precise and, for this reason, they are present in workshops.
Lastly, we find belt or mixed grinders —with belt and disc—. These teams, in addition to the abrasive disc, include a sanding band. They are ideal for plumbing workshops, since the band allows to work with irregular and cylindrical pieces.
There can’t be a grinder comparison without talking about discs. These machines work with disks (one or two) attached to a shaft that, together with the electric motor, makes them rotate at high speeds. The discs are made of abrasive materials and have “grains” that can be more or less thick. The diameter of these discs ranges between 150 and 200 mm, depending on the size of the grinder, although there are some machines that accept larger sizes.
Discs with a finer grain are used for finishing and sanding work, especially for wet work. The coarse grain ones are ideal for hard work, especially for metals.
In addition to abrasive grinding discs, you can also use metal bristle brush discs. These discs are designed for grinding and cleaning metals. There are wavy ones, which are more aggressive; braided, which are indicated for cleaning joints and welding and, finally, cup, for hard-to-reach surfaces such as corners.
Less powerful grinders will have trouble working hard parts. It is usual in compact equipment that, when supporting the piece on the disk, it stops. This is because the motor does not have enough force to move the grain of the discs through the imperfections in the metal and therefore the friction that occurs causes the spindle to stop.
The power indicates the work capacity of the machines, the higher the number of watts, the more powerful the grinder will be. You should also know that the power directly influences how much the machine costs.
There are 70 W, which are usually light models to transport, and others with greater power, exceeding 700 W. These more powerful models are used in mechanical workshops, since they can rough and machine thick metal parts. A good and cheap grinder usually has a power of 400 or 500 W, which, in most cases, turns out to be enough for any home workshop.
The best quality grinders have electronic systems to regulate the speed of rotation of the discs. These systems allow the user to select the speed of rotation of the disk, which allows better control of the finishes.
This is a very useful function for polishing jobs and those in which greater precision is required, since it will allow the turning speed to be adapted to each situation in which it is found, to the material with which it is working and to the function that it is working on. you want to give to the grinder.
A good grinder should last for years, even with heavy use it should last. For this, it must be made with the best materials so that it has the robustness that allows it to withstand all kinds of DIY tasks, both domestic and professional. It is also convenient that the casing is made of metals such as wrought iron or aluminum.
Along with the robust construction, it should have an anti-vibration system. Most have some anchoring system, usually holes to screw the machine to a work table. Some, on the other hand, have rubber feet or bottom surfaces that allow them to absorb vibrations.
The best grinders on the market will have a series of accessories such as protection glasses for discs or tool holders. The first ones are adjustable and protect the operator from sparks and accidents due to reaching, if a piece of the disc or the tool with which he is working comes off. The supports are pieces that are attached to the casing of the disk and serve to support the piece with which you work, whether they are drill bits, edges or metal pieces. Some have tilt adjustment for easy operation.
Some models of grinders have certain extras that can be very useful such as built-in dust extractors, LED work lights and power buttons protected by rubber to prevent discharges and protection systems against overloads and overheating.
Frequently asked questions
Q1: How to use a grinder?
Now that you know everything about grinders, you should learn how to use them. First of all, it is important that you understand that they are machines with electric motors, so they must be connected to the current.
To use it, you just have to turn it on and wait for the discs to start spinning. It is important that you always use the central part of the disc and never the edges, as you could lose control of the tool. Discs often have glass guards that you need to adjust to prevent sparks from reaching you.
Now you just have to sharpen the tools. To sharpen a knife or cutting tool, you will need to rest the blade on the surface of the disc. To work with a flat screwdriver or a bit, you must respect the angle of the tip, some grinders have pieces to support the tools; use these accessories to properly sharpen these equipment.
Q2: How to sharpen knives with a grinder?
Sharpening a knife with a grinder is a quick and easy system to keep the edge always alive and in good condition. To do this, all you have to do is put the blade of the knife over the indentation and turn on the machine. The device itself will take care of making the knife perfectly sharp. Always keep a good angle so that the edge looks good and, above all, check it when you finish and give it a pass with a steel or a stone manually.
Q3: How to take apart a DeWalt grinder?
Before disassembling a DeWalt grinder, we recommend that if you don’t know how to do it, don’t do it, as you could assemble it wrong and the machine will stop working.
Now, the first thing you have to do is remove the cable from the light. Once it’s off, remove the disc(s). Find the case screws and, using the appropriate screwdriver, remove them completely and store them for easy access.
Once you have removed the two parts of the casing (being careful not to pull any internal cable, especially the ground cable), you already have the grinder disassembled.
Q4: How to make a homemade grinder?
The first thing you will need is an electric motor. Although you can choose one as powerful as you want, with one between 100 and 200 W you will have more than enough. At this point, the most important thing is that you choose a motor capable of moving the axis. The number of revolutions must never exceed 1500, as it could be dangerous. Ideally, the motor should have feet or clamping systems and a 220V input.
Install the motor on a stable frame. Place the shaft on the side of the motor and fit the abrasive disc on it. For this, the output shaft must have the same diameter as the hole inside the disc. The disc must be secured by means of a flange and a bolt with washer.
Turn on the grinder and check that everything works fine. It is very important that the electrical connections of the motor are correct, otherwise the machine will not work.
Q5: What can be done with a grinder?
A grinder is a very useful power tool. The most common is to use it for polishing and polishing metals. In machine shops it is used to rough cut parts and to remove burrs from previously machined metal parts. Machine shops also use grinders to clean welds on parts.
In more domestic settings, they are used primarily for sharpening cutting tools and for grinding cuts or polishing parts.
Q6: What is a pedestal grinder?
Pedestal grinders are machines with two abrasive discs —one on each side— and larger than bench grinders. These machines are used for heavier work such as weld cleaning and deburring large castings. These grinders have powerful motors up to 5 horsepower.
Q7: How to sand with a grinder?
The pieces to be sanded must be held with both hands, since the disc has a lot of power and could rip them out of your hands. Always use the protection glass of the machine and protective glasses, as well as gloves and a mask, since a lot of dust is formed when sanding.
The materials to be sanded must rest on the disc or band, holding them firmly, but without pressing or exerting force. Move the piece and let the grain do the work.
Q8: How to repair a grinder?
Repairing a grinder will depend on the problem you have. If the axis “dances”, it will surely be a problem with the bearings, so you will have to change them. If the ignition fails, you will have to check all the wiring and the electronic board; if any are burnt, you’ll need to replace them. If the switch fails, you’ll have to change it too.